The invention relates to a heat treatment technique of a thick-wall aluminum alloy hollow extruded section. After double-stage reinforced solution treatment is carried out on the aluminum alloy section, three-stage artificial aging is sequentially carried out. By adopting the double-stage reinforced solution treatment, part of soluble phases can be firstly dissolved, thereby lowering the stored energy of deformation of the alloy, eliminating most stress in the structure, and inhibiting the subsequent recrystallization and coarse crystal grains; and the second phase and insoluble phase in the structure are further dissolved, thereby enhancing the degree of supersaturation of the quenched alloy. The three-stage aging treatment is implemented by interrupting the traditional single-stage aging, so that the alloy has the structure characteristics of the dispersive and fine intracrystalline precipitated phase and the isolated and discontinuous grain boundary precipitated phase; and the three-stage aging treatment intercepts the intercrystalline corrosion channel and enhances the corrosion resistance of the alloy. Compared with the traditional technique, the technique provided by the invention enhances the strength of the aluminum alloy section by 15% or above on the premise of not lowering the plasticity, obviously improves the corrosion resistance, and is simple and easy to implement and convenient for industrial production. The technique is especially suitable for heat treatment reinforcement of aluminum alloy hollow extruded sections for rail transit.

Heat treatment technique of thick-wall aluminum alloy hollow extruded section

The invention provides a preparation method and device of an additive method rapidly-set fully equiaxed crystal aluminum alloy cast ingot. The device comprises a metal heating mechanism and a negativepressure cooling mechanism. The metal heating mechanism is located above the negative pressure cooling mechanism and connected with the negative pressure cooling mechanism through a nozzle. The negative pressure cooling mechanism comprises a vacuum chamber with an air inlet and an exhaust hole, and a three-dimensional moving ingot mechanism arranged in the vacuum chamber. The three-dimensional moving ingot mechanism comprises a moving ingot and a two-dimensional moving platform vertically connected with the moving ingot. A water cooling mechanism is arranged outside the moving ingot, and themoving ingot is driven by a precision motor to precisely move up and down. By means of the technological means of changing atomized spraying into liquid-state injection, the density of the alloy ingotis improved, oxidization of the alloy ingot is relieved, meanwhile, the production efficiency of the cast ingot is improved, and aluminum and the alloy cast ingot thereof with a fully equiaxed crystal structure and without macro-element segregation can be rapidly prepared.

Preparation method and device of additive method rapidly-set fully equiaxed crystal aluminum alloy cast ingot

The invention provides a method for improving the size stability of an aluminum alloy for aerospace, and belongs to the technical field of nonferrous metal machining. The method includes the step that an LY12 aluminum alloy subject to dual-stage homogenization treatment is sequentially subject to multi-pass hot rolling, multi-pass reversing cold rolling, dual-stage solid solution water quenching treatment and dual-stage aging treatment, and the aluminum alloy which is uniform in grain size, stable in tissue and smaller in residual stress is obtained. Compared with a conversional treatment method, the method for obtaining the LY12 aluminum alloy has the beneficial effects that the surface residual stress of the aluminum alloy can be effectively reduced by 10 MPa to 50 MPa, the micro yield strength of the aluminum alloy can be improved by 30 MPa to 60 MPa, and the size change is smaller than 0.01% after the aluminum alloy is placed at the indoor temperature for more than half a year. The method is easy and convenient in operation process, the cost is lower, the technological process is greatly simplified, and the treated aluminum alloy is uniform in grain size, stable in tissue and small in residual stress. The method has a quiet positive effect on improving the using accuracy of aerospace inertial components in China and prolonging the service life of the aerospace inertial components in China. The method is suitable for industrial production.

Method for improving size stability of aluminum alloy for aerospace

The invention relates to a manufacturing method for a 3D printing additive of an electronic packaging shell. According to the method, high-volume-fraction silicon carbide particles and aluminum powderare evenly mixed into a powder metallurgy raw material, a 3D printing additive manufacturing technology is adopted, and the SiCp/Al composite material shell of an integrated structure is net-formed.The problem of poor wettability between silicon carbide particles and aluminum liquid is solved by carrying out surface modification pretreatment on the silicon carbide particles, and the contact angle is changed from 118 degrees to 57 degrees; and the manufactured shell has the small density, high bending resistance and compressive strength, high thermal conductivity, small thermal expansion coefficients, uniform compositions and no defects, such as cracks, the size precision and roughness meet the requirements of design specifications, and a guarantee is provided for the rapid batch manufacturing of electronic packaging shells for equipment in the aerospace field.

Manufacturing method for 3D printing additive of electronic package shell

The invention discloses a spray forming method for an aluminum-lithium alloy. The spray forming method comprises the following steps that (1) materials are weighed according to mass percentages of chemical components of the alloy; (2) the components of the aluminum-lithium alloy are melted in a smelting furnace, and a covering agent is added for protection, wherein the melting temperature is 700-800 DEG C; (3) alloy melt is refined at the refining temperature of 700-750 DEG C; (4) the refined alloy melt is subjected to standing for 10-30 min, and then filtering is conducted; and (5) the filtered alloy melt is injected into a bottom pouring ladle, and the alloy melt is sprayed from refractory spray nozzles to a receiving plate to be formed. A spray forming device is adopted, and an aluminum-lithium alloy round ingot is accurately formed by adjusting the spraying angle, the atomization air pressure, the melt superheat temperature, and the lowering speed and the rotating speed of the receiving plate, and the spray forming method has the advantages that the compactness of a finished product is high, the chemical components are uniform without macrosegregation, the forming speed is high, the process stability is good, and the rate of finished products is high.

Spray forming method for aluminum-lithium alloy

The invention relates to aluminum-lithium alloy, in particular to a method for manufacturing a three-dimensional large-size aluminum-lithium alloy round ingot through spray forming. Ar atomization is adopted, spray forming is carried out on aluminum-lithium alloy melt which is subjected to gas removing, slag removing, refining and filtering, and a cylindrical ingot blank is formed; through optimization combination of adjustment of the spraying angle, atomization air pressure, the melt superheating temperature, the receiving disc descending speed and the rotating speed, rapid, precise and compact forming of the aluminum-lithium alloy melt is achieved, and the forming rate is not lower than 10 kg/min; the obtained ingot blank is regular in shape, high in compactness and free of chemical component macrosegregation, and the diameter of the ingot blank can reach phi 650 mm; the yield of the large-size aluminum-lithium alloy ingot blank produced through the method is more than 80%.

Method for manufacturing three-dimensional large-size aluminum-lithium alloy round ingot through spray forming

The invention relates to 7000 series aluminum alloys, in particular to a heat treatment method capable of reducing stress of spray-formed 7000 series aluminum alloy products. The heat treatment method comprises a two-stage solid solution treatment step and an artificial ageing treatment step sequentially and is characterized in that after the artificial ageing treatment step and before rough machining or after the rough machining and before finish machining, high-temperature stress-relieving aging is performed, that is, heat preservation is performed at the temperature of 125-155 DEG C for 8-32 h. The heat treatment method can maintain the higher strength level of the spray-formed 7000 series aluminum alloy products, reduce residual stress efficiently and improve the comprehensive performance of the products, the problem of cracking of the products in follow-up machining process is solved, machining deformation of the products is reduced, the machining efficiency is improved, and the dimensional precision is improved.

Heat treatment method capable of reducing stress of spray-formed 7000 series aluminum alloy products

The invention discloses an utralight spacecraft propellant container. The utralight spacecraft propellant container comprises spray-formed hemispherical first housing and second housing made of an aluminum alloy material 7055; and a circular membrane made of a pure aluminum material and deformed elastically and plastically along the surface vertical direction of the container. The membrane is installed between the first housing and the second housing. The membrane is welded at the lower part of the first housing through a TIG welding technology. The first housing and the second housing are welded and connected by a stirring friction welding technology. The first housing and a first connecting seat are formed by forging, heating and finish-machining processes, and the second housing and a second connecting seat are formed by the same forging, heating and finish-machining processes. The utralight spacecraft propellant container is capable of, through the spray-formed super-strength aluminum alloy material 7055, reducing the wall thickness of the container body, and realizing the ultralight goal.

Utralight spacecraft propellant container

The utility model discloses a spray process silicon -aluminium alloy's cooling system, this system is by the deposit surface cooling system of the first order and the deposition chamber cooling system of the second level, gaseous supply system, gas cooling device and the spray tube of deposit surface cooling system for connecting gradually through the pipeline, deposition chamber cooling system assembles the pipeline by heat sink, cooling device, heat -conducting medium inlet distribution pipeline and heat -conducting medium export and forms. The utility model discloses a doublestage cooling method is solved spray process in -process deposition chamber and deposit surface temperature and too high and reduce the solidification speed problem of sial granule, overcome prior art's cooling efficiency low and can not be to deposit surface direct cooling not enough.

Spray process silicon -aluminium alloy's cooling system

The invention discloses a cooling system and method for spray forming of silicon-aluminum alloy. The system is composed of a first-level deposition surface cooling system and a second-level deposition room cooling system. The deposition surface cooling system comprises a gas supplying system, gas cooling devices and spraying pipes, wherein the gas supplying system, the gas cooling devices and the spraying pipes are connected in sequence through pipelines. The deposition room cooling system comprises heat sucking devices, a cooling device, a heat conduction medium inlet distribution pipeline and a heat conduction medium outlet gathering pipeline. According to the two-level cooling method, the problem that the temperature of a deposition room and the temperature of a deposition surface are too high in the spray forming process, and consequently the solidification velocity of silicon-aluminum particles is reduced is solved, and the defects that in the prior art, the cooling efficiency is low, and the deposition surface cannot be directly cooled are overcome.

Ma Wantai

Papers

Method for manufacturing three-dimensional large-size aluminum-lithium alloy round ingot through spray forming

Heat treatment method capable of reducing stress of spray-formed 7000 series aluminum alloy products

Utralight spacecraft propellant container

Spray process silicon -aluminium alloy's cooling system

Cooling system and method for spray forming of silicon-aluminum alloy